English
Related papers

Related papers: Testing Fractional Action Cosmology

200 papers

We use FIRAS and Planck 2015 data to place observational bounds on inflationary scenarios in multi-fractional spacetimes with $q$-derivatives. While a power-law expansion in the geometric time coordinate is subject to the usual constraints…

High Energy Physics - Theory · Physics 2016-08-23 Gianluca Calcagni , Sachiko Kuroyanagi , Shinji Tsujikawa

This work examines the cosmological implications of two functional forms of $f(R,T) = R + \alpha T^n$ gravity: for two different value of $n $ where $n=1$ and $n\neq 1$, and $\alpha$ and $n$ are free parameters. The modified Friedmann…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-24 Mustapha Lamaaoune

The complexity and accuracy of current and future precision cosmology observational campaigns has made it essential to develop an efficient technique for directly combining simulation and observational datasets to determine cosmological and…

Astrophysics · Physics 2009-11-11 Katrin Heitmann , David Higdon , Charles Nakhleh , Salman Habib

We investigate the evolution of matter density perturbations within a fractional cosmological framework inspired by fractal space-time constructions in field theory, where a deformation of the integration measure induces non-locality and…

General Relativity and Quantum Cosmology · Physics 2026-04-24 S. M. M. Rasouli

A Friedman cosmology is investigated based on scalar-tensor gravitation with general metric coupling and scalar potential functions. We show that for a broad class of such functions, the scalar field can be dynamically trapped using a…

General Relativity and Quantum Cosmology · Physics 2016-10-05 C. H. -T. Wang , J. A. Reid , A. St J. Murphy , D. Rodrigues , M. Al Alawi , R. Bingham , J. T. Mendonca , T. B. Davies

A Friedmann like cosmological model in Einstein-Cartan framework is studied when the torsion function is assumed to be proportional to a single $\phi(t)$ function coming just from the spin vector contribution of ordinary matter. By…

General Relativity and Quantum Cosmology · Physics 2019-11-21 S. H. Pereira , R. de C. Lima , J. F. Jesus , R. F. L. Holanda

We study cosmological evolution in a flat FLRW spacetime in the context of modified STEGR gravity or $f(Q)$, using an exponential two-parameter model which represents a smooth perturbative expansion around the $\Lambda$CDM model. The…

General Relativity and Quantum Cosmology · Physics 2025-04-15 Ivan R. Vasquez , A. Oliveros

Dynamical aspects of cosmological model in an extended gravity theory have been investigated in the present work. We have adopted a simplified approach to obtain cosmic features, which in fact requires more involved calculations. A…

General Relativity and Quantum Cosmology · Physics 2021-06-10 B. Mishra , S. K. Tripathy , Sankarsan Tarai

Possible formulations of the problem of cosmic rays acceleration in the interstellar galactic medium are considered with the use of fractional differential equations. The applied technique has been physically justified. A Fermi result has…

Astrophysics of Galaxies · Physics 2011-05-19 V. V. Uchaikin

Understanding the evolution of dark energy poses a significant challenge in modern cosmology, as it is responsible for the universe's accelerated expansion. In this study, we focus on a specific $f(T)$ cosmological model and analyze its…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-14 A. Zhadyranova , M. Koussour , S. Bekkhozhayev , V. Zhumabekova , J. Rayimbaev

We present methods to rigorously extract parameter combinations that are constrained by data from posterior distributions. The standard approach uses linear methods that apply to Gaussian distributions. We show the limitations of the linear…

Cosmology and Nongalactic Astrophysics · Physics 2022-04-06 Tara Dacunha , Marco Raveri , Minsu Park , Cyrille Doux , Bhuvnesh Jain

We probe the cosmic expansion scenario within the framework of $f(R, L_{m})$ gravity by employing a well-motivated functional form of $f(R, L_{m}) = \frac{R}{2} + L_{m}^{\lambda}$. Specifically, we introduce three novel cosmological models…

General Relativity and Quantum Cosmology · Physics 2026-05-27 Khomesh R. Patle , G. P. Singh

We extract observational constraints on $f(T)$ gravity, using the recently proposed statistical method which is not affected by the value of $H_0$ and thus it bypasses the problem of the disagreement in its exact numerical value between…

Cosmology and Nongalactic Astrophysics · Physics 2018-08-15 S. Basilakos , S. Nesseris , F. K. Anagnostopoulos , E. N. Saridakis

We use dynamical system methods to explore the general behaviour of $f(T)$ cosmology. In contrast to the standard applications of dynamical analysis, we present a way to transform the equations into a one-dimensional autonomous system,…

General Relativity and Quantum Cosmology · Physics 2018-03-14 A. Awad , W. El Hanafy , G. G. L. Nashed , Emmanuel N. Saridakis

The following review presents an attempt to discuss various issues of current interest in Observational Cosmology, the selection of which as well as the emphasis given, reflects my own preference and biases. After presenting some…

Astrophysics · Physics 2007-05-23 M. Plionis

In this paper, we present the cosmological scenario obtained from $f(R,T)$ gravity by using an exponential dependence on the trace of the energy-momentum tensor. With a numerical approach applied to the equations of motion, we show several…

General Relativity and Quantum Cosmology · Physics 2019-11-11 G. Ribeiro , R. Sfair , P. H. R. S. Moraes , J. R. L. Santos , A. de Souza Dutra

Gaussian processes provide a method for extracting cosmological information from observations without assuming a cosmological model. We carry out cosmography -- mapping the time evolution of the cosmic expansion -- in a model-independent…

Cosmology and Nongalactic Astrophysics · Physics 2012-07-11 Arman Shafieloo , Alex G. Kim , Eric V. Linder

We perform a cosmographic analysis using several cosmological observables such as the luminosity distance moduli, the volume distance, the angular diameter distance and the Hubble parameter. These quantities are determined using different…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-30 Jun-Qing Xia , Vincenzo Vitagliano , Stefano Liberati , Matteo Viel

Inspired by an exponential $f(R)$ gravity model studied in the literature, in this work we introduce a new and viable $f(Q)$ gravity model, which can be represented as a perturbation of $\Lambda$CDM. Typically, within the realm of $f(Q)$…

Cosmology and Nongalactic Astrophysics · Physics 2024-01-31 A. Oliveros , Mario A. Acero

The article investigates cosmological applications of $f(Q)$ theories in a non-coincident formalism. We explore a new $f(Q)$ theory dynamics utilizing a non-vanishing affine connection involving a non-constant function…

General Relativity and Quantum Cosmology · Physics 2024-10-03 Sneha Pradhan , Raja Solanki , P. K. Sahoo